Presentation: Efficacy and Safety of Pregabalin as Long-Term Treatment of Pain Associated with Fibromyalgia: A 1-Year, Open-Label Study (2007)

1523 Efficacy and Safety of Pregabalin as Long-Term Treatment of Pain Associated with Fibromyalgia: A 1-Year, Open-Label Study

Introduction: Pregabalin has demonstrated efficacy for the treatment of pain associated with fibromyalgia syndrome (FM) in 4 randomized clinical trials. We report on a study evaluating the long-term efficacy and safety of pregabalin to treat FM- associated pain.
Methods: In this 1-year, open-label (OL) extension study, eligible patients had participated in a 13-week randomized, placebo-controlled trial (RCT) of pregabalin dosed 300-600 mg/d (BID) as treatment of FM-associated pain. Following their RCT termination visits, patients had the option of continuing to receive pregabalin under OL conditions, starting at 300 mg/d, with dosage escalation to 150-600 mg/d. Efficacy was assessed by changes from baseline to endpoint in the Short-Form McGill Pain Questionnaire (SF-MPQ), including sensory and affective pain descriptors and total score, Present Pain Intensity (PPI), and Visual Analog Scale (VAS).
Results: 429 of 431 screened patients entered OL treatment, 249 (58%) completed the study, 70 (16.3%) discontinued due to an adverse event (AE), 44 (10.3%) defaulted, 66 (15.4%) discontinued for other reasons. 399 patients (93%) were women, 396 (92.3%) were white; mean age was 48.3 years (range, 19-75). Patients’ FM had mean duration of 9.4 years (range 0.5 to 52 years). Median duration of treatment with pregabalin was 357 days (range, 1-402 days); 286 patients (66.7%) received pregabalin for ≥26 weeks, while 114 received pregabalin for ≥1 year. Overall exposure was 303 patient years, with the greatest exposure, 100.5 patient years, occurring at 600 mg/d (BID). Mean change from baseline to endpoint in SF-MPQ sensory, affective, and total scores indicated improvement, as did mean change from baseline to endpoint in VAS and PPI scores: VAS decreased 21 points (0-100 scale), while PPI decreased 0.9 point (0-5 scale). The most frequently reported all-causality AEs were dizziness, somnolence, peripheral edema, and increased weight, most of which were mild to moderate in intensity and of limited duration. Dizziness was the cause of 6 discontinuations, and somnolence and increased weight were the cause of 5 discontinuations each. 22 patients (5.1%) had serious AEs, and 5 of these patients discontinued. Serious AEs in all but 2 patients were considered to be unrelated to study treatment. There were no clinically meaningful changes in laboratory values associated with pregabalin treatment.
Conclusions: In this OL study of pregabalin administered for up to 1 year, long-term treatment with pregabalin was associated with improvement in pain associated with FM. Pregabalin in dosages of 150-600 mg/d (BID) was generally well tolerated by these patients with FM, and the AE profile emerging from this long-term study was consistent with that previously reported.

  H. Florian, Pfizer Employee, 3; J.P. Young, Pfizer Employee, 3; G. Haig, Pfizer Employee, 3; J. Barrett, Pfizer Employee, 3.